Fuel burner



' June 14, 1938. E. v. MICHAUD 2,120,257

FUEL BURNER Filed Jan. 18, 1932 l v El gya/ZZZW.

Patented June .14, 1938 FUEL BUaNEn Elzear V. Michaud, Chicago, Ill., assignor of twoifths to Raymond D. Schnoor, and one-fifth to Robert F. Miehle, Jr., both of Chicago, Ill.

Application January 18, 1932, Serial No.. 587,338l

6Claims.

This invention relates in general to a fuel burner and more particularly to a method of improving combustion in burners and to burning apparatus.

An important object of the invention is to provide a method of conditioning fuel as an incident to the burning thereof whereby an increased efl'iciency and greater heating capacity are effected.

In similar apparatusprovided heretofore com- 10 bustion is incomplete and far b`elow actualand inherent possibilities. This is evidenced by yellow and blue flames, smoke, carbon deposits, low eat generation, etc. In accordance with my invention the fuel, particularly liquid fuel such.

as oil, is conditioned to effect more perfect combustion which is evidenced by violet to invisible flame, no carbon deposit or smoke and greater heat generation per unit quantity of fuel as well as a higher degree of heat.

m) Another object is to providefapparatus for practicallyvapplying the method and wherein coking such as may obstruct the operation of burning is prevented. In previously provided similar apparatus preheating elements become clogged after a period of use by carbon deposits on the interior thereof rendering the apparatus inoperative. By preventing the accumulation of these deposits consistent and dependable operation of a burner` is effected. Y

Other objects such as the economic design, ad-

justability and the like, willbe apparent asthe invention is better understood from the following description when considered in connection with the accompanying drawing forming apart hereof.

3:, Referring to the drawing- Figure 1 is a plan view of an apparatus embodying my invention; and

Figure 2 is a longitudinal sectional view taken substantially on line 2--2 in Figure l. Y

40 `In accordance with my invention oxygen is combined with .conditioned fuel which is then expanded by exposure to heat to effect maximum combustion.

Liquid fuels such as the volatile 'oils when heated are expanded to vapor and then to gases in succession. The transition to vapor taking place for example in relatively heavy fuel oils at approximately 125 F. and to gas at approximately '150 F. By heating the gases beyond '150 F. they are expanded proportionately and if permitted to cool or condense in the presence of oxygen, such as in atmospheric air, oxygen will be absorbed in proporiton to the extent of condensation. The ideal proportions of oxygen to fuel for .f ubstantially complete combustion has been determined as '14 t`o 1 and to substantially `saturate the gasiiled fuel with oxygen, I prefer to preheat the fuel to approximately 1200 to A 1500 F. or more and then to expose the expanded l gases to oxygen preferably in free air such as by 5 discharging the fuel through a mixing tube of suitable diameter, which is determined by the volume of gas discharged, and of a length proportional to a normal velocity of the gases to permit contraction of the gas moleculesto approxi- 10 mately 750 F. without permitting material condensation, thus effecting substantially complete saturation \of the gas molecules with oxygen.

To further condition the gases or mixtures of elements they are then superheatedto' effect a 15 substantial reexpansion.

One form of apparatus or burner for lapplying the above described method'includes a jet valve Il, and a mixing tube Iv2'mounted in a fixture I3,

a preheating element It 4and a nre pot I5. 20

The jet valve Il may be any suitable de ce fcr releasing the fuel in a jet stream or the like and into the mixing tube I2, and in the present embodiment includes a body 2| in which a valve needle 22 isv mounted as indicated for adjust- 25 ment relative to a valve seat 23 by means of a suitable handle or wheel 2l.

A sleeve 20 of frustro-conical form and having a threaded connection with the valve body 2| facilitates adjustment for controlling the relative 30 proportions of air in accordance with the requirements of the various grades of fuel obtainable and suitablev for use in the apparatus.

The mixing tube I2 is preferably a metallic tube capable of withstanding a high degree of 35 heat and is of such a diameter as to vafford a proper combustion mixture and a relatively low velocity of the combustion mixture through the tube. The tube I2 is relatively long to provide a sufficient length of time in effecting the com- 40 bustion mixture to the end that an intimate combustion mixture be formed.

- The fixture I2 maybe any suitable bracket or fitting having a bearing portion 21 in which the tube I2 may be mounted for longitudinal adjust- 45 ment and in which the valve Il may be mounted or secured in alinement with the tube I2 as indicated.

The valve II may be rigidly secured in the iixture I3 -in any suitable manner and the tube I2 50 may be secured in adjusted relationship with respect to the valve .Il by means of a set screw 28 or the like. Y

The preheatingelement Il is preferably a tubular conductor arranged in or about the nre pot 55 I5 or kformed spirally about the fire pot end of the tube I2 as shown. In the present embodiment this element is formed of a material capable of withstanding extreme heat wrapped to form a close Wound internal helical coil 3l and a clos'e wound external helical coil 32 closely nested on the internal coil. The coils 3| and 32 being connected or formed of a continuous tube and connected to an extended portion 33 of the valve body 2| through connecting tubes 34 and 35 integral therewith and suitably connected to the portion y33 as indicated.

In accordance with my invention the tubes 34 and 35 are interconnected to form a closed fuel circuit through the coils 3| and-32 and a connecting or by-pass channel 36 formed in the extended portion 33 of the valve body 2| or the Fuel is supplied tothe closed circuit under pressure from a tank 31 or other source of supply through a tube 38 suitably connected to the valve portion 33 and delivered to the restricted outlet jet of the valve 2| through an extended portion 39 of the channel 36 as indicated.

Means is provided for insuring a unidirectional flow through the by-pass channel 36 in the direction from the outlet side of the preheating element I4 to the inlet side thereof, and, as shown, this means consists of check valve comprising an upwardly facing valve seat 4I formed in the channel 36 anda check ball 42 engaging downwardly'pn the seat under the influence of gravity.

A pin 43 formed on an adjustable 'st/op plug 44 extends into the channel 36 to limit upward or opening movement of the ball 42.

The burner apparatus may be attached to a fire box 45 or to other apparatus by means of a mounting bracket 46'suitably secured to the fire box as indicated having a bearing portion 41 in which the burner apparatus may be longitudinally adjusted and rigidly secured in adjusted relationship by means of a set screw 48 or the like.

The fire pot I5 is preferably formed of lava or similar material capable of resisting at least 3500 F. of heat. Essentially the fire pot I5 is a hood covering the combustion end of the mixing `tube I2 and the coils 3| and 32 with one or more openings such as an opening 5I of sufficient total capacity to permit maximum heat radiation while .retaining sufficient heat in the re pot I5 to pro-- ing bracket 46 as indicated or arranged in the fire box 45 in any suitable manner.

rIl'he burner is started by'opening the valve II and at least partially filling a sump 55 formed in the fixture I3, igniting the fuel in the sump to start generation of gas with the valve I closed.

After a brief period vaporizing is started, at which time the valve I I may then be opened and while combustion is relatively low with vaporized fuel the flame rapidly settles down t'o relatively complete combustion as sufficient heat is accumulated to gasify and expand the gasiiied fuel. burner is functioning normally the combustion is sustained in the flre pot I5 at the inner or outlet end of themixing tube I2, at,which end the preheating element I4 is, disposed.-

Assuming the burner to be functioning normally, liquid fuel under lpressure in the tank 31 passes from the tank through the-tube 38 into the channel 35 above the check ball 42 engaged.

When the on the seat 4I, then into the tube 34, and then into the inner coil 3| of the preheating element I4.

In'the gasification of the fuel in the preheating or gasifying element I4, sudden momentary expansions take place in this element and, due

'to the inertia of the liquid fuel in the fuel feed line and the inner coil 3|, these sudden expansions cause momentary excess pressure on the gasied fuel in the outer coil 32 outlet tube 35, the extended portion 39 of the channel 36 below the valve Iseat 4I and in the valve 2|, that is to say, at the outlet lside of the element I 4.

When such an expansion takes place, the resulting excess pressure at the outlet side of the element I4 causes the lifting of the check ball 42 from its seat 4I and a flow of gas into the fuel line which ceases and permits the check ball 42 to again engage the seat 4I upon pressure equilibrium being again established between the inlet and outlet sides of the element I4, the check ball 42 and its seat preventing a flow through the by-pass channel 36 from the inlet side of the element I4 to the outlet side thereof.

As a result of this action, not only is excess pressure diierenceat the outlet jet, which results in the burner surging, prevented, but the bypass,-entering the fuel line,- serves to prevent coking in and consequent clogging of the element I4, at least to such an extent, as proven by extended-test, that the element I4 will function indefinitely. In addition a portion of the bypassed gas enters the tank 31 through the tube 38 as a xed gas and maintains the pressure in the tank despite the flow of fuel therefrom.

'I'he exact functioning of the by-pass in the prevention of coking in the element I4 is not delnitely known to me, but it is my theory that the by-passed gas, entering the system in circulation controlling relation. with the element I4 and opposing backward movement of the liquid fuel therefrom, maintains a substantially constant and violent circulation in the element I4 and thus prevents the anchoring of carbon therein. At

any rate, in operation the' pulsations through.

' relatively long foi the proper mixture of the fuel gas issuing from the jet of the valve 2| with a supporter of combustion, such as air as shown,

and by reason of the fact that the inner coil 3| is connected with.the fuel source and thus remains relatively cool, this coil tends to prevent overheating of the outlet end of the mixing tube .and consequent back firingA in the mixingI tube.

It is thought that thel invention and many of its attendant advantages will be understood from the foregoing description, and' it will be apparent that various changes may be made in the form, construction, and arrangement of the parts without departing from vthe spirit and scope of the invention, or'sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In adevicelof the character described the combination of a conduit having a conditioning portion one end of which is connected with a` liquid supply under pressure and the other end of which is providedwith av restricted outlet, an additional conduit connecting said conduit at the outletand inlet ends of said portion to pro- Vportion one end of which is connected with a liquid supply under pressure and the other end of which is provided with a restricted outlet, a by-pass conduit connecting said conduit at the outlet and inlet ends of said portion to provide a flow from the outlet end to the inlet end of said portion upon excess pressure occurring at said 'outlet end, and a check valve for preventing a l iow through said b'y-pass conduit to said outlet end.

3. In a liquid fuel system the combination with a pressure tank, of a conduit having a conditioning portion one end of which is connected with said tank for the supply of liquidtherefrom and stricted outlet, and additional conduit connecting said conduit at the outlet and inlet ends of said portion to provide a flow from the outlet end to the inlet end of said portion uponexcess pressure occurring at said outlet end, and means for preventing aow of liquid through said additional conduit to said outlet end.

4. In a'liquid fuel system the combination with a pressure tank, of a conduit having a conditioning portiononefend of which is connected with said tank for the supply of liquid therefrom and the other end of Which is provided Witha restricted outlet, a by-pass conduit connecting said conduit at the outlet and inlet ends of said portion to providea ow from the outlet end t-o the inlet end of said portion upon excess pressureoccurring at'said outlet end, and a check valve associated with said by-pass conduit for preventing a flow through said by-pass conduit f to said outlet end. l

5.A In a liquid fuel burner the combination of a burner tube, a lconduit having a conditioning portion comprising nested inner and outer helical coils surrounding said burner tube in the region of its outlet end and having the ends thereof corresponding with the outlet end of the' burner tube connected, the end of said inner coil which is remote from the outlet end of said burner tube being connected with a source of .liquid fuel supply, an outlet jet device connected-With the end of the outer coil which is remote. from the outlet end of the burner tube and said jet device being disposed remote from the outlet end of the burner tube to project fuel through the burner tube toward the outlet end thereof, and means responsive to excess pressure at the outlet jt end of the outer coil and effective upon the liquid in the conduitv between the fuel inlet end of the inner coil and said source of supply to oppose backward movement of the liquid from the inner coil. 6. In a liquid fuel burner the combination of a burner tube, a conduit havinga conditioning portion comprising closely nested inner and outer helical coils Asurrounding said burner tube in the region of its outlet end and having the ends l thereof corresponding with the outlet end of the -jet device being disposed remote from the outlet end of the burner tubefto project fuel through the burner tube toward the outlet end thereof, a by-pass conduit connecting the outlet jet end of the outer coil with thev fuel inlet end of the inner vcoil, and a check valve associated with said bypass conduit forpreventing a flow through said by-pass conduit to the outlet jet end of said outer coil.

ELZER V. MICHAUD. 

